> the instructions of the red light have to be followed regardless

No they don't. If there's no enforcement, and no moral reason to follow the law, you've reduced yourself to a robot if you follow it.

As far as red lights are concerned though, you'd better be damn sure cars or bikes or pedestrians aren't going to leap out from around a corner before you run them. Especially if the intersection is empty at 3am and visibility is poor. In fact in that situation it's better to play it safe.

If there is no camera and no police, you can run treat the light as a stoplight. Just be safe about it.

By can, I mean that a human being can choose to do so. Maybe smart cars in the future won't allow the driver to make that decision. But nothing forces us to always obey traffic laws right now.

Enforcement is just a technicality.

In China and many other countries, rules are typically so numerous, draconian or fuzzy that you are nominally constantly breaking something. If the authorities want to alter your behavior, they call in the specter of potential enforcement to encourage behavioral change. On the one hand this seems horrible - shifting sands, constant unknowns, zero security - but in reality it's kind of liberating - less need to hire lawyers and asking for forgiveness is tolerated. The gap between enforcement and law is precisely where most people seek to operate, because it typically creates additional efficiencies. In short, enforcement is law. Or to rephrase this in the words of Snowden - Policy is a one-way ratchet that only loosens over time.